Rotary kinetic device with coplaner tandem pistons

ABSTRACT

A rotary kinetic fluid device such as a pump, compressor or motor has a rotor with angularly related tandem piston assemblies therein whose axes are all disposed in a common plane and that are caused to reciprocate in the rotor by securement to bearing races that are eccentric to the rotor and concentric to each other. Diametrically opposed pistons are interconnected in tandem by connections that laterally overlie each other in the intersecting piston bores.

United States Patent Casey 51 Aug. 1, 1972 [54] ROTARY KINETIC DEVICE WITH COPLANER TANDEM PISTONS [72] Inventor: Leonard R. Casey, Rte. 5, Box 533 C, Claremore, Okla. 74017 [22] Filed: Sept. 29, 1970 [21] App]. No.: 76,547

[52] US Cl ..9l/493 [51] Int. Cl ..F04b 13/06 [58] Field of Search ..91/491, 492, 493, 496; 417/462 [56] References Cited UNITED STATES PATENTS 3,331,326 7/1967 Casey ..9l/496 2,831,438 4/1958 Goinard ..91/493 FOREIGN PATENTS OR APPLICATIONS 479,961 5/1916 France ..91/492 351,803 5/1905 France ..9l/493 542,268 6/1956 Italy ..91/49l 596,262 4/1925 France ..91/496 Primary Examiner-William L. Freeh AttorneyYoung & Thompson [5 7] ABSTRACT A rotary kinetic fluid device such as a pump, compressor or motor has a rotor with angularly related tandem piston assemblies therein whose axes are all disposed in a common plane and that are caused to reciprocate in the rotor by securement to bearing races that are eccentric to the rotor and concentric to each other. Diametrically opposed pistons are interconnected in tandem by connections that laterally overlie each other in the intersecting piston bores.

1 Claim, 2 Drawing Figures ROTARY KINETIC DEVICE WITH COPLANER TANDEM PISTONS The present invention relates to rotary kinetic fluid devices of the type in which a rotor has a plurality of pistons reciprocable therein along a plurality of diametral lines, all points on each piston moving in circular paths eccentric to the axis of rotation of the rotor. The present invention is equally well applicable to pumps, motors and compressors, that is, the rotor may drive or may be driven by the liquid or gaseous kinetic fluid; but in the disclosure that follows, the invention will be described and illustrated in connection with a pump.

It is an object of the present invention to provide a rotary kinetic fluid device in which the rotor is desirably small and well balanced.

Another object of the present invention is the provision of such a device in which high pressures can be obtained or utilized with good efficiency.

Finally, it is an object of the present invention to provide such a device which will be relatively simple and inexpensive to manufacture, easy to assemble, install, operate, maintain and repair, and rugged and durable in use.

Other objects and advantages of the present invention will become apparent from a consideration of the following description, taken in connection with the accompanying drawing, in which:

FIG. 1 is a cross-sectional view of a device according to the present invention, viewed in the direction of its axis of rotation, taken on the line 1-1 of FIG. 2; and

FIG. 2 is an axial cross-sectional view of a device according to the present invention.

Referring now to the drawing in greater detail, there is shown a device according to the present invention in the form of a pump having a casing 1 containing a concentric rotor 3 that bears against lands 5 by which the pump chamber within the casing is divided into an inlet chamber 7 that receives liquid from a source of supply (not shown) through an inlet 9, and outlet chamber 11 that discharges liquid to a receiver (not shown) through an outlet 13.

Rotor 3 is in the form of a cylinder 15 mounted coaxially on a drive shaft 17 which is rotated by a source of power (not shown) and is carried in a conventional manner in fluid-tight hearings in casing 1. The side walls of cylinder 15 are in sliding contact with the inner side walls of easing l; and it is a feature of the present invention, as seen in FIG. 2, that the axial extent of cylinder 15 can be relatively quite small.

Casing 1 is made up of two casing halves 19 which can be mirror images of each other and which contain confronting annular recesses 21 that are coaxial with rotor 3. Each recess 22 is bordered radially inwardly by a central boss 23 and radially outwardly by an annular shoulder 25 integral with the associated casing halves l9. Disposed in each recess 21 is a pair of ball bearing assemblies, the inner assembly 27 having its inner ball race force fitted about boss 23 and the outer ball bearing assembly 29 having its outer ball race force fitted within shoulder 25.

Cylinder 15 is transected by a plurality of intersecting diametrically disposed through bores 31 and 33 whose axes lie in a common plane. In each of these bores, there is disposed a tandem piston assembly 35 made up of two coaxial pistons 37 and 39. A ROD 41 integral with piston 37 extends parallel to but offset from the common axis of pistons 37 and 39 and the associated bore and fixedly interconnects the two pistons 37 and 39 in tandem relationship. Rod 41 at its outer end has a threaded shank 43 thereon that terminates in the direction of piston 37 in a shoulder 45. The piston 39 has a bore therethrough parallel to but offset from its axis, which receives shank 43, the piston 39 abutting against shoulder 45 to fix the position of piston 39 on shank 43. The bore of piston 39 is counterbored to receive a spanner nut 47 that threads on the outer end of shank 43 fixedly but removably to secure piston 39 in tandem relationship with piston 37.

The pistons of the other tandem piston assembly need not be separable from each other but can be integral, as assembly and disassembly of the pistons with respect to the rotor can be effected if one tandem piston assembly 35 is inseparable and the other assembly or assemblies 35 can be assembled and disassembled. Therefore, in a device as shown in the drawing, in which there are two tandem piston assemblies, only one need be made separable as shown in FIG. 2

The other tandem piston assembly 35 also has a rod 41 interconnecting its two pistons, the two rods 41 laterally overlying each other in the intersection of bores 31 and 33.

The piston 37 of each assembly 35 is transected diametrically by a pin 49 parallel to the axis of rotor 3 and projecting at opposite ends from both sides of piston 37. The side walls of the bores 31 and 33 are transected by laterally aligned radially disposed slots 51 in which the ends of pins 49 reciprocate radially of rotor 3. The opposite ends of pins 49 thus extend into and orbit coaxially in recesses 21 in the casing halves 19. The free ends of the pin 49 associated with one tandem piston assembly 35 are rotatably received in a sleeve 53 carried by the outer ball race of the inner ball bearing assembly 27. The free ends of the pin 49 carried by the other tandem piston assembly 35 are rotatably received in a sleeve 55 carried by the inner ball race of the outer ball bearing assembly 29.

In operation, rotor 3 rotates clockwise as seen in FIG. 1, the liquid being drawn into the inlet chamber 7 as the piston 39 moves downwardly and being expelled from the outlet chamber 11 as the piston 37 also moves downwardly, the pistons of the other assembly 35 then performing the same functions as they move out of the vicinity of the lands 5, and so on in alternation as in the usual operation of a rotary piston kinetic fluid device of the general type of the present invention. The adjacent ball races of the bearing assemblies 27 and 29 revolve with their associated piston assemblies, and their associated sleeves 53 and 55 accordingly have precession relative to each other but never interfere with each other, the innermost and outermost ball races of the assemblies 27 and 29, respectively, remaining stationary with their associated casing halves 19. The rods 41 of the piston assemblies 35 have reciprocal movement relative to each other during their rotation with their respective piston assemblies, and may or may not be in sliding contact with each other. v

It is thus to be noted that, by the provision of the pistons with their axes all in a common plane, it is possible to make the cylinder 15 of the rotor 3 as thin as possible along the axis of the drive shaft 17. Not only is a rotor of desirably small size and low weight thus achieved, but also it is possible to reduce the size of the inlet and outlet chambers 7 and 11 thereby to permit the achievement of relatively higher pressures for a given pump size, with resultant increase in efficiency of pump operation.

The provision of the pistons with their axes lying in a common plane also makes it much simpler to balance the rotor and to guide the pins 49 and to provide a smoothly running pump that sufiers minimum wear in operation.

From a consideration of the forgoing disclosure, therefore, it will be evident that all of the initially recited objects of the present invention have been achieved.

Although the present invention has been described and illustrated in connection with a preferred embodi ment, it is to be understood that modifications and variations may be resorted to without departing from the spirit of the invention, as those skilled in this art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention as defined by the appended claims.

Having described my invention, 1 claim:

1. A rotary kinetic fluid device comprising a casing having inlet and outlet chambers therein and a rotor rotatable in the casing and a plurality of diametral bores through the rotor having piston means in the bores, the axes of the bores being disposed at an angle to each other and lying in a common plane, said rotor having radially disposed slots therethrough communicating with each said bore on opposite sides of each said bore, a pin carried by each said piston means and extending in opposite directions beyond said piston means through and beyond both slots associated with each said bore, said casing being comprised by two casing halves containing confronting annular recesses coaxial with said rotor, each recess being bordered radially inwardly by a central boss and radially outwardly by an annular shoulder integralwith the associated casing half, a pair of ball bearing assemblies disposed in each recess, the radially inner assembly having an inner ball race secured about said boss and the radially outer ball bearing assembly having an outer ball race secured within said shoulder, the outer bearing race of said radially inner ball bearing assembly being rotatably secured to said pin of one said piston means, the inner bearing race of said radially outer ball bearing assembly being rotatably secured to said pin of another of said piston means, said bearing races being disposed symmetrically on opposite sides of said rotor. 

1. A rotary kinetic fluid device comprising a casing having inlet and outlet chambers therein and a rotor rotatable in the casing and a plurality of diametral bores through the rotor having piston means in the bores, the axes of the bores being disposed at an angle to each other and lying in a common plane, said rotor having radially disposed slots therethrough communicating with each said bore on opposite sides of each said bore, a pin carried by each said piston means and extending in opposite directions beyond said piston means through and beyond both slots associated with each said bore, said casing being comprised by two casing halves containing confronting annular recesses coaxial with said rotor, each recess being bordered radially inwardly by a central boss and radially outwardly by an annular shoulder integral with the associated casing half, a pair of ball bearing assemblies disposed in each recess, the radially inner assembly having an inner ball race secured about said boss and the radially outer ball bearing assembly having an outer ball race secured within said shoulder, the outer bearing race of said radially inner ball bearing assembly being rotatably secured to said pin of one said piston means, the inner bearing race of said radially outer ball bearing assembly being rotatably secured to said pin of another of said piston means, said bearing races being disposed symmetrically on opposite sides of said rotor. 